A few days ago I looked at Kings Cross Wikipedia .One picture shows a Craven diesel railcar in York Road platform. Reputedly the last Moorgate service in March .In the photo in front of the diesel railcar there is a ground Disc signal in front of what was 8 points along the UP Moorgate line.. Now this signal was never there when the Old Power Box was operational . It must have been approx. 60 ft. in rear of the up LUL controlled signal . Anyone know what brought about this signal? Was it operational or a fixed signal because of the points.

Assuming in rear, the answer may be in John's diagram https://signalbox.org/diagrams.php?id=1136 of 1971. At that time 3/7 signal was just in rear of 8, with a disc 6 on the post below the multi-aspect heads. So I wonder if 3/7 had been superseded (presumably part of the stageworks) but 6 was still required, so renewed as a facing shunt.

If you put Kings Cross station on your computer ,scroll down to Kings Cross Wikipedia ,then scroll through till you get the picture of Kings Cross yard taken looking towards a Craven unit standing in York Road platform. look at the front of the diesel unit and in front non drivers side opposite platform is the mystery disc signal.You could say the only route available wrong direction along the up slow to the limit of shunt in the tunnel in rear of number 8 points. Was this signal provided for the first Thameslink upgrades? As it was Absolute Block with T C s . The signal was installed when the OCS panel in the present Panelbox was operational. 3/7 signal with 6 disc was still operational.

John Hinson wrote:I really can't think of any benefit in placing a signal there (or retaining the LOS Board) as I don't think there would be any reason for a set back move after the South Spur was abolished in 1971.

I'm inclined to believe the Wiki-quoted date of 31/10//76 for the photo rather than March, as the diesel services stopped just before the new through Northern City Line service Finsbury Park / Moorgate commenced on 08/11/76 [I'd actually thought that they continued into the next week; until Fri.05th or Sat.06th Nov.]

However, train service cessation apart, I'm sure that John's diagram is correct, and this disc, which I struggle to understand as being 'facing', was only provided post-1971 (I must confess that, though I knew the layout and its alterations pretty well, I don't recall this item at all).1976 was a trifle early to have much to do with Thameslink work I think.

If the mystery disc was a working one, I'd have thought that re-using the former South Spur GF release lever, 5, to work it might have involved the least alterations to any locking, and would also have been in a very logical position in the frame for such a function.As to usefulness, all I can think of is that, if workable rather than fixed, it might've (just about?) allowed a loco to be stabled between it and the platform Starter KC4/OJ21*(perhaps even until the resignalling but after the Up Met. line was no longer used), protecting No.8 points, and being cleared towards the LOS in the tunnel when the loco was required in order to move to the approach side of 3 / 6 / 7 signal to move into Platform 1 (the tops of 3 & 7 signal heads are actually visible in the photo above the DMU roof, in line with the driver's side windscreen pane).

* - (I thought I recalled LT Kings Cross 'C's number for this as being OJ 1; Notes check required.)

I vaguely remember a disc being installed but I will ask some S&T lads who were there during that period if they remember a disc signal being installed. Could it have been in transit by staff we moved them about complete with disc face, and the staff had put the disc down ?

scarpa wrote:If you put Kings Cross station on your computer ,scroll down to Kings Cross Wikipedia ,then scroll through till you get the picture of Kings Cross yard taken looking towards a Craven unit standing in York Road platform. look at the front of the diesel unit and in front non drivers side opposite platform is the mystery disc signal.You could say the only route available wrong direction along the up slow to the limit of shunt in the tunnel in rear of number 8 points. Was this signal provided for the first Thameslink upgrades? As it was Absolute Block with T C s . The signal was installed when the OCS panel in the present Panelbox was operational. 3/7 signal with 6 disc was still operational.

Sorry, my mistake, I'd assumed it was for a right-direction move (and didn't have time, at the time, to chase up the original image so relied on the description).

On a point of detail it was TCB (by bell) in the Up Direction, with slots as StevieG describes, and AB only on the Down (Hotel Curve).

StevieG wrote:However, train service cessation apart, I'm sure that John's diagram is correct, and this disc, which I struggle to understand as being 'facing', was only provided post-1971 (I must confess that, though I knew the layout and its alterations pretty well, I don't recall this item at all).1976 was a trifle early to have much to do with Thameslink work I think.

If the mystery disc was a working one, I'd have thought that re-using the former South Spur GF release lever, 5, to work it might have involved the least alterations to any locking, and would also have been in a very logical position in the frame for such a function.

[snip]

The interlocking of said signal would not have any benefit by choice of number as my diagram represents the changes with the transfer to the new box and commissioning of the ("temporary") switch panel 26/9/71. So we are only talking electrical locking for panel switches.

StevieG wrote:If the mystery disc was a working one, I'd have thought that re-using the former South Spur GF release lever, 5, to work it might have involved the least alterations to any locking, and would also have been in a very logical position in the frame for such a function.

[snip]

The interlocking of said signal would not have any benefit by choice of number as my diagram represents the changes with the transfer to the new box and commissioning of the ("temporary") switch panel 26/9/71. So we are only talking electrical locking for panel switches.

Are there any plans available showing post Kings Cross layout available? Are there any former signalman or supervisors who may be able to assist? I know one of the last supervisors retired and lives in Cornwall .I have one S&T guy to ask . Could this be a phantom signal like the Banner signal at Greenford that disappeared?